mean proportional

American  

noun

Mathematics.

1. (between two numbers a andb ) a number x for which a/x = x/b .

   The number 3 is a mean proportional between 1 and 9.

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Etymology

Origin of mean proportional

First recorded in 1565–75

Example Sentences

The second of three numbers is a mean proportional between the other two.

From A Review of Algebra by Rivenburg, Romeyn Henry

Then the whole line DC is 141,289; and CP, which is a mean proportional between DC and CN, since MD touches the Ellipse, will be 105,032.

From Treatise on Light by Huygens, Christiaan

Then the whole line CZ is 139,655; and CS, which is a mean proportional between CZ and CO will be 93,410.

From Treatise on Light by Huygens, Christiaan

We then find the mean proportional between the length HD and the height of the parallelogram.

From Amusements in Mathematics by Dudeney, Henry Ernest

Define ratio, proportion, mean proportional, third proportional, fourth proportional.

From A Review of Algebra by Rivenburg, Romeyn Henry